为什么@autowired不能在泛型dao类中工作？

时间：2015-09-24 10:27:59

标签： java spring autowired

通用类

package com.messaging.dao;   
import java.io.Serializable;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.persistence.Column;
import javax.persistence.Id;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Restrictions;
import org.springframework.beans.factory.annotation.Autowired;

import com.messaging.utils.OrderBy;

public abstract class GenericDaoHibernateImpl<T,PK extends Serializable>
implements GenericDao<T,PK> {
    private transient final Class<T> clazz;
    private transient Field idField;
    private transient final List<Field> columnFields = new ArrayList<>();
    //private String table;
    //private PK key;
    @Autowired
    private SessionFactory sessionFactory;

    @SuppressWarnings("unchecked")
    public GenericDaoHibernateImpl() {
        Type t = getClass().getGenericSuperclass();
        ParameterizedType pt = (ParameterizedType) t;
        clazz = (Class<T>) pt.getActualTypeArguments()[0];
        /*table = clazz.getDeclaredAnnotation(Table.class).name();*/
        for(Field field : clazz.getDeclaredFields()) {
            if(field.isAnnotationPresent(Column.class)) {
                field.setAccessible(true);
                if(field.isAnnotationPresent(Id.class))
                    idField = field;
                columnFields.add(field);
            }
        }   
    }

    @SuppressWarnings("unchecked")
    @Override
    public PK create(T newInstance) {
        return (PK) getSession().save(newInstance);
    }
    @Override
    public void createOrUpdate(T newInstance) {
        getSession().saveOrUpdate(newInstance);
    }
    @Override
    public T getById(Serializable id) {
        return getSession().get(clazz, id);
    }
    @Override
    public void update(T transientObject) {
        getSession().update(transientObject);
    }

    /*public void update(PK id, T transientObject) {
        Session session = getSession();
        session.createCriteria(clazz).add(Restrictions.idEq(id));

    }*/
    @Override
    public void delete(T persistentObject) {
        getSession().delete(persistentObject);
    }
    @Override
    public void delete(Serializable id) {
        T t = getById(id);
        getSession().delete(t);
    }

    @SuppressWarnings("unchecked")
    public List<T> getList(T criteria, OrderBy orderBy, Integer page, Integer pageSize) throws IllegalArgumentException, IllegalAccessException {
        return getCriteria(criteria,orderBy,page,pageSize).list();
    }
    @Override
    public Map<Serializable, T> getMap(T criteria) throws IllegalArgumentException, IllegalAccessException {
        Map<Serializable, T> tMap = new HashMap<>();
        @SuppressWarnings("unchecked")
        List<T> tList = getCriteria(criteria).list();
        for(T t: tList) {
            Serializable idVal = (Serializable) idField.get(t);
            tMap.put(idVal, t);
        }
        return tMap;
    }

    public Criteria getCriteria(T criteria) throws IllegalArgumentException, IllegalAccessException {
        return getCriteria(criteria, null, null, null);
    }

    public Criteria getCriteria(T criteria, Integer pageNumber, Integer pageSize) throws IllegalArgumentException, IllegalAccessException {
        return getCriteria(criteria, null, pageNumber, pageSize);
    }

    public Criteria getCriteria(T criteria, OrderBy orderBy) throws IllegalArgumentException, IllegalAccessException {
        return getCriteria(criteria, orderBy, null, null);
    }

    public Criteria getCriteria(T criteria, OrderBy orderBy,Integer pageNumber, Integer pageSize) throws IllegalArgumentException, IllegalAccessException {
        Criteria where = getSession().createCriteria(clazz);
        for(Field field : columnFields) {
            where.add(Restrictions.eq(field.getDeclaredAnnotation(Column.class).name(), field.get(criteria)));
        }
        if(orderBy!=null)
            where.addOrder(orderBy.getHibernateOrder());
        if(pageNumber!=null && pageNumber>0 && pageSize!=null && pageSize>0) {
            where.setFirstResult((pageNumber-1)*pageSize);
            where.setMaxResults(pageSize);
        }
        return where;
    }

    private Session getSession() {
        return this.sessionFactory.getCurrentSession();
    }

    @SuppressWarnings("unchecked")
    @Override
    public T get(T criteria) throws ReflectiveOperationException {
        return (T) getCriteria(criteria).uniqueResult();
    }
}

简单的Dao实现

package com.messaging.dao;
import org.springframework.stereotype.Repository;

import com.messaging.dto.UserDTO;
@Repository
public class UserHibernateDao extends GenericDaoHibernateImpl<UserDTO, Integer> implements UserDao {

    public UserHibernateDao() {
        super();
    }

    @Override
    public UserDTO getUserByLogin(String login) throws ReflectiveOperationException {
        UserDTO user = new UserDTO();
        user.setLogin(login);
        return get(user);
    }

}

的web.xml 

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
         http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
  <display-name>Messaging Service</display-name>
  <filter> 
       <filter-name>springSecurityFilterChain</filter-name> 
       <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> 
    </filter> 
    <filter-mapping> 
       <filter-name>springSecurityFilterChain</filter-name> 
       <url-pattern>/*</url-pattern> 
    </filter-mapping>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class>
    </listener>
    <servlet>
        <servlet-name>messaging-service</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>messaging-service</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <jsp-config>
        <jsp-property-group>
            <url-pattern>*.jsp</url-pattern>
            <page-encoding>UTF-8</page-encoding>
        </jsp-property-group>
    </jsp-config>
</web-app>

的applicationContext.xml 

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
    http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd">

    <context:annotation-config />
    <context:component-scan base-package="com.messaging" />
    <mvc:annotation-driven />
    <tx:annotation-driven />

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/views/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <import resource="messaging-service-servlet.xml"/>
    <import resource="security.xml" />
</beans>

消息接发服务-servlet.xml中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
    http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd">

    <mvc:default-servlet-handler/>

    <mvc:resources mapping="/resources/**" location="/resources/bootstrap/"/>

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
      <property name="driverClassName" value="com.mysql.jdbc.Driver" />  
      <property name="url" value="jdbc:mysql://localhost:3306/messaging_service?autoReconnect=true" />  
      <property name="username" value="root" />  
      <property name="password" value="127" />  
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan" value="com.messaging.dto"/>
        <property name="hibernateProperties">
            <props>
                <prop key="show_sql">true</prop>
                  <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
            </props>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

</beans>

当我在GenericDaoHibernateImpl中调用方法时，sessionFactory为null。可能是什么问题呢？请帮助

0 个答案:

没有答案
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